Apparatus for processing tubular metal work-pieces



0a. 15, 1935. B AN T 2,017,387

APPARATUS FOR PROCESSING TUBULAR METAL WORK PIECES Filed Sept. 21, 1933 2 Sheets-Sheet l [menfofx 5E Y47N7" 514/V/V/5 75g Patented Oct. 15, 1935 UNITED STATES PATENT OFFICE APPARATUS FOR PROCESSING TUBULAR METAL WORK-PIECES 1 Claim.

This invention relates to the manufacture of seamless pipes and tubes from cast or rolled billets, and more particularly to apparatus for materially reducing the wall thickness of a tubular 5 blank, or work piece, and considerably elongating it without any substantial change in diameter.

The tubular blank, or work-piece, is usually maintained in proper position between the metal working rolls by stationary guiding members located above and below the same. These guiding members offer considerable resistance to both rotational and longitudinal movement of the metal.

In my oo-pending application, entitled Method and apparatus for forming tubular blanks, Serial No. 670,345, filed May 10, 1933, novel extraneous assisting forces are disclosed for assisting both rotational and longitudinal travel .of a workpiece through a piercing operation. These extraneous forces comprise a pair of substantially cylindrical power-actuated feed rolls which are disposed intermediate the metal working rolls with a slight angle of inclination to the center line of the mill. ency resulting from the cross-setting of these power-actuated feed rolls is greater than the forward feeding tendency of the metal working rolls with equal surface speeds.

One object of the present invention is the provision of a novel apparatus for increasing the speed of delivery of wall reducing and elongating operations, while simultaneously maintaining a very orderly movement of the metal in such manner as to positively assist both longitudinal and rotative movement of the metal.

Another object is the provision of novel means for controlling the perimeter of a tubular workpiece while efiecting a very substantial reduction in its wall thickness, resulting in the production of an unusually thin walled tubular blank which is free from the usual surface defects.

These and further objects will be apparent after referring to the drawings, in which:

Figure 1 is a plan of the apparatus of the invention with one. of the extraneous assisting forces removed, and showing the work-piece in section.

Figure 2 is a side elevation of the apparatus 66 with one metal work roll removed.

the reeling section of the novel metal working pass of the invention.

Figure 4 is a composite view disclosing the relationship of one metal working roll to one of the feed rolls which is shown, together with a portion The longitudinal feeding tend- Figure 3 is a sectional end elevation taken in.

of the billet, in a plane substantially degrees from its true position in the mill.

Referring more particularly to the drawings, the numeral 2 designates a pair of barrel-shaped metal working rolls of the cross-roll type which 5 are disposed with their axes inclined to each other and to the axis of the tubular blank or work-piece they are intended to process. The metal working rolls when taken together provide elongated converging surfaces 2 parallel surfaces 2 and di- 10 verging surfaces 2.

The novel extraneous assisting forces of the in= vention comprise a pair of substantially cylindrical power-actuated feed rolls 3 which are disposed intermediate the metal working rolls 2 and 1 in a manner somewhat similar to the latter, but with their angles of inclination to the center line of the mill slightly greater than the corresponding inclination of the metal working rolls. These power-actuated feed rolls 3 when taken together 20 provide elongated converging surfaces 3 which are grooved annularly, relatively narrow converging surfaces 3* which are smooth, and substantially parallel surfaces 3 and diverging surfaces 3, and are driven in such manner that these. surfaces, which contact with a work-piece pro-, gressing between the metal working rolls 2, travel at a speed at least equal to the surface speed of the metal working rolls. The longitudinal feeding tendency resulting from the cross-setting of the feed rolls is at least equal to the forward feeding tendency of the metal working rolls 2 with equal surface speeds, and may, of course, be increased by either increasing the angularity of the feed rolls or their surface speeds.

A mandrel 4 is positioned within the tubular blank, or work-piece, which is indicated at A, during the processing operation. I I

Referring to Figure 3 of the drawings, a pair of small stationary guiding members 5 are profiled to permit of close proximity to the metal working rolls 2 and the feed rolls 3, and are disposed to permit a small contact area 5? to limit the lateral bulging of-the work-piece A, particularly as the forward and rearward ends thereof are passing under the rolls.

In operation, the tubular blank, or work-piece A, is introduced into the converging section of the pass where its horizontal diameter is slightly reduced until the inner wall contacts the mandrel 4, after which further progress through the pass results in a decrease in wall thickness. Throughout this section, the elongated and corrugated converging surfaces of the feed rolls act to effectively grip the metal of the work- 55 piece as each successive increment thereof is fed from the metal working rolls 2, resulting in a diversion of metal from circumferential to longitudinal flows and at the same time the work-piece is assisted in both rotational and longitudinal travel through the pass.

As the metal of the work-piece progresses through the parallel section of the metal working pass which is defined by the surface 2 of the metal working rolls and the corresponding surface 3 of the feed rolls, a reeling operation will accrue, resulting in a uniform wall thickness and smooth internal and external surfaces which are free from scores and roll marks.

The contact of the feed rolls 3 with the work piece A ceases at the end of the substantially parallel portions 3'.

The work-piece A continues through the reeling section and enters the diverging section of the pass defined by the diverging surfaces 1 of the metal working rolls, while the horizontal diameter of the oval increases and the vertical diameter decreases a like amount until it is perfectly round, after which it loses contact with these rolls.

While I have shown and described one embodiment of my invention, it will be understood that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of my invention, as defined in the following claim.

I claim:

In an apparatus for elongating a tubular metal work-piece the combination of an elongated cylindrical mandrel, reducing rolls disposed in cooperative relation with the mandrel to form a 5 pass and cause the blank to bulge laterally away from the mandrel and to move the metal of the blank helically, said reducing rolls including a conical wall reducing portion and a cylindrical reeling portion with their wall-reducing portions 10 materially longer than their individual remaining portions and substantiallyconvergent with respect to each other, and blank-feeding means including blank-engaging cross feed rolls including elongated conical portions and cylindrical l5 portions located in the pass with their axes lengthwise thereof, said feed rolls extending lengthwise of the pass for contact with the blank longitudinally thereof to limit bulging of the blank and to apply extraneous feeding forces to 30 the blank for assisting both the longitudinal and peripheral components of the movement of the metal, said feed rolls having their elongated conical portions peripherally grooved for furthering the longitudinal component and having their 25 contact surfaces spaced a materially greater distance from the longitudinal center line of the pass than the corresponding surfaces of said reducing rolls.

BRYANT BANNISTER. 

